Filter systems in industrial or stationary applications are used in a multiplicity of processes, for example for filtering out liquid or solid particles from a gas flow or solid particles from a liquid flow. To this end, the respective filter system uses at least one filter body which separates an inlet space from a clean space inside the system. To this end the filter body has a filter material through which the respective fluid can flow and which is impermeable for the particles which are to be filtered out. In the course of the cleaning operation or filtering operation the filtered out particles can accumulate or deposit on the filter material, that is, on the inlet side of the filter body. This increases the flow resistance of the filter body. In order that the filtering operation does not have to be interrupted, or only has to be interrupted for a short time, modern filter systems can be equipped with a backflush device, with the aid of which the filter body can be backflushed with a suitable rinse medium. The backflushing then takes place counter to the filtering direction, that is, from the clean side to the inlet side. This means that the impurities which have deposited on the inlet side of the filter body can be removed. Such a backflush device can operate with at least one backflush nozzle, with the aid of which the respective rinse medium is applied to the clean side of the filter body. To this end, such a backflush nozzle can have a multiplicity of openings through which the rinse medium flows in a flow direction, which is defined by the longitudinal axis of the opening, and exits from the backflush nozzle during backflushing. The rinse medium passes through such point-like openings at a corresponding backflush pressure with a straight jet or with a jet which fans out in a cone-shaped manner out of the respective opening and impinges on the filter body over a corresponding circular impact area.